1. Field of the Invention
The present invention relates to the field of image and graphics processing and printing and in particular, to systems and methods for outlining differences between high resolution images.
2. Description of Related Art
When digital high resolution images are used, the images are often compared to determine differences between the images. The comparing of images may arise in the context of both graphics and image processing applications. For example, in image processing, when multiple image processing algorithms are used to process the same input image, comparing the output images may be useful in determining differences in the output images produced by the various algorithms. As another example, when a printer is being tested with various rendering intent or color mapping algorithms it may be useful to compare the bit mapped output images produced by the algorithms against “gold standard” images or the images produced by another printer as they exist in frame buffer memory of the printer.
One approach to comparing the images is to print the images on a high resolution printer or display the images on a high resolution monitor in order to identify differences by visually inspecting the images. However, such an approach, besides being time consuming, is unlikely to yield consistent results. Moreover, even the most detailed visual inspection will fail to catch minor image differences, or image differences that may be masked because of the nature of the images.
Another approach is to calculate the difference in digital images by comparing corresponding pixels in the two images on a pixel-by-pixel basis and produce an output difference image based on the pixel differences between the images being compared. However, in such an approach, large numbers of inconsequential differences between pixel values may appear in the difference image making it difficult to focus on differences between the two images that a user may deem important. Therefore, there is a need for systems and methods to permit the outlining of image differences between images in a flexible manner that permits quick and easy identification of image differences.